The invention constitutes an improvement in the art set forth in my earlier U.S. Pat. No. 4,173,532 issued Nov. 6, 1979 and also entitled "Method For Treating Plant Effluent". Since many of the details of this invention are to be found in the disclosure of the foregoing patent said details are incorporated by reference herein. While the method of the invention, as is the case of the prior invention, is primarily directed to the separation of waste materials from the water in the effluent of an industrial plant such as a cake baking plant or a donut making plant, it is also more broadly useful for the treatment of sanitary wastes. My earlier U.S. Pat. No. 4,173,532 is a physical-chemical process. The present invention, however, is a physical chemical-biological process, including primary, secondary and tertiary treatments. It is a principal object of this invention to get pure, drinkable water from waste water which is bad or non-drinkable. The treated water should have the lowest possible level of BOD (BiologicalOxygen Demand) and COD (Chemical Oxygen Demand).